1. Field of the Invention
This invention relates to a tool for extracting a selected contact pin from a multipin electrical header connector.
2. Description of the Related Art
A header assembly, or header, as shown in FIG. 1, has a pin mounting wall within which are releasably held a preselected number of contact pins within a preselected plurality of pin mounting holes passing through the wall and arranged in a rectilinear matrix. The wall extends between a pair of generally rectangular resilient fastener legs (not shown) with connector elements for snap fit connection with a back plane header mounting assembly. The header mounting assembly mounts a plurality of headers with their contact pins on one side of the header wall to associated circuit elements.
From time to time it becomes necessary to remove a contact pin from a header on site in order to effectuate repairs. For this purpose it has been known to employ a signal pin extraction tool which has a pair of spaced fingers mounted at the end of an elongate handle within which is mounted a mechanism including an actuator adjacent an end of the handle opposite the pair of spaced fingers. The actuator is linked to the pair of fingers to draw them together to grasp a contact pin and to lock the fingers in a grasping position with respect to the contact pin to be extracted. Reference should be made to the Torlon Bushings Manual Berg PN#413723, Rev. A, ECR V61275, published by Berg Electronics, of Etters, Pa., Oct. 10, 1996.
A number of problems or difficulties are presented when attempting to use the known signal contact pin extraction tool. First, the pair of spaced fingers are mounted within a bore of a tool head which extends on opposite sides of the spaced fingers beyond the contact pin locations located immediately adjacent to and on opposite sides of the contact pin to be extracted. Consequently, the head is required to have a pair of pin alignment holes on opposite sides of the pair of spaced fingers for receipt of the contact pins located on opposite sides of the pair of spaced fingers when the contact pin to be extracted is received between the pair of spaced fingers. Because the entire bodies of the adjacent contact pins are received within the pin alignment holes and the contact pin alignment holes can only be seen at the face of the head within which they are located, visibility of both the object contact pin to be extracted and the pair of adjacent contact pins is obscured by the tool head. The obscured vision makes it difficult to properly align the pair of spaced fingers and the pin alignment holes with the object contact pin and the adjacent contact pins.
Another problem arises because the head surrounds and encloses the pair of spaced fingers the width of the forward gap between the pair of fingers within which the object pin is to be received is reduced relative to the full width of the head. This results in a relatively greater accuracy required to insert the object contact pin within the forward gap between the pair of fingers. In addition, the full length of lateral gaps on opposite sides of the forward gap are not accessible for receipt of the object contact pin because the fingers and the lateral gaps are partly surrounded by the head even when the fingers are in a maximally extended position relative to the face of the head. Both of these circumstances relatively increase the difficulty of aligning the object contact pin for receipt between the pair of spaced fingers.
Another problem associated with the known contact pin extraction tool results from a complicated actuator for actuating and locking the pair of fingers in a grasping relationship with the contact pin which employs a pivotally mounted lever. The lever is moved in one direction to open the gap between the fingers. Release of the lever closes the fingers, and pivotal movement of the lever in a another direction is required to lock the fingers in grasping relationship with the contact pin.